There is a known method of manufacturing a crystal material by allowing a part of a melt of a metal containing material to fall freely (which refers to a fall from an initial speed of zero) through a small hole provided at a bottom of a container and letting a droplet impinge upon a cooling member, thereby solidifying the crystal material (Patent Document 1).
In this case, examples of the metal containing material include a metal such as titanium and iron, an alloy such as titanium-nickel, copper-aluminum, and copper-indium, a semiconductor such as germanium, silicon, indium-antimony, iron-silicon, and copper-indium-selenium, and a ceramic such as an alumina-garnet composite material.
Examples of the cooling material include a metal such as copper and iron and a ceramic such as glass and aluminum nitride.
The diameter of a droplet is in the range from 0.1 mm to 50 mm, preferably from 2 mm to 10 mm.
The distance for free fall is set to such a distance that a droplet is not solidified until it impinges upon the cooling member and about 1 to 50000 times as large as the length of the droplet (diameter) in the vertical direction.
In a conventional method of manufacturing a crystal material, a quartz glass plate is placed in a position 6.5 m vertically below a small hole used to let a droplet to fall freely and a droplet is allowed to fall freely through the small hole, so that a crystal is produced on the quartz glass plate.
Patent Document 1: JP 2001-89292 A
Non-Patent Document: T. Okada, S. Higashi, H. Kaku, H. Murakami, and S. Miyazaki: “Analysis of Transient Temperature Profile During Thermal Plasma Jet Annealing of Si Films on Quartz Substrate,” Jpn. J. Appl. Phys. 45 (2006) pp. 4355-4357.